id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
afs-72114	Mettälä, Aila; Koponen, Maarit; Pirinen, Heikki; Korkman, Johan	The effect of fertilization and crop rotation on soil chemical and biological properties. Field trials on a clay soil in Southern Finland	1982	14	.pdf	application/pdf	5092	316	54	Since the total amounts of nitrogen (0.3 %) did not differ appreciably, it appears that neither nitrogen fertilizer application nor the clover-timothy ley had a long-term effect on nitrogen content in the soil in question. While the nitrogen content of the soil may vary according to the proportion of legumes in the ley (CLEMENT 1961), the cultivation of legumes does not necessarily increase nitrogen content, although it always results in activation of the soil nitrogen (LYON 1930).	cache/afs-72114.pdf	txt/afs-72114.txt